Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752847AbbGEIet (ORCPT ); Sun, 5 Jul 2015 04:34:49 -0400 Received: from mail-la0-f53.google.com ([209.85.215.53]:34470 "EHLO mail-la0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751086AbbGEIej (ORCPT ); Sun, 5 Jul 2015 04:34:39 -0400 MIME-Version: 1.0 In-Reply-To: <1435312710-15108-2-git-send-email-gioh.kim@lge.com> References: <1435312710-15108-1-git-send-email-gioh.kim@lge.com> <1435312710-15108-2-git-send-email-gioh.kim@lge.com> Date: Sat, 4 Jul 2015 21:49:35 +0300 Message-ID: Subject: Re: [RFCv2 1/5] mm/compaction: enable driver page migration From: Konstantin Khlebnikov To: Gioh Kim Cc: Jeff Layton , Bruce Fields , Vlastimil Babka , Joonsoo Kim , Al Viro , "Michael S. Tsirkin" , Minchan Kim , Rafael Aquini , linux-fsdevel , virtualization@lists.linux-foundation.org, Linux Kernel Mailing List , Linux API , "linux-mm@kvack.org" , Andrew Morton Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5640 Lines: 153 On Fri, Jun 26, 2015 at 12:58 PM, Gioh Kim wrote: > Add framework to register callback functions and > check pages migratable. > There are some modes of page isolation so that isolate interface > has an arguments of page address and isolation mode. > > Signed-off-by: Gioh Kim > --- > include/linux/compaction.h | 11 +++++++++++ > include/linux/fs.h | 2 ++ > include/linux/page-flags.h | 19 +++++++++++++++++++ > include/linux/pagemap.h | 27 +++++++++++++++++++++++++++ > 4 files changed, 59 insertions(+) > > diff --git a/include/linux/compaction.h b/include/linux/compaction.h > index aa8f61c..4e91a07 100644 > --- a/include/linux/compaction.h > +++ b/include/linux/compaction.h > @@ -1,6 +1,9 @@ > #ifndef _LINUX_COMPACTION_H > #define _LINUX_COMPACTION_H > > +#include > +#include > + > /* Return values for compact_zone() and try_to_compact_pages() */ > /* compaction didn't start as it was deferred due to past failures */ > #define COMPACT_DEFERRED 0 > @@ -51,6 +54,10 @@ extern void compaction_defer_reset(struct zone *zone, int order, > bool alloc_success); > extern bool compaction_restarting(struct zone *zone, int order); > > +static inline bool driver_page_migratable(struct page *page) > +{ > + return PageMigratable(page) && mapping_migratable(page->mapping); > +} > #else > static inline unsigned long try_to_compact_pages(gfp_t gfp_mask, > unsigned int order, int alloc_flags, > @@ -83,6 +90,10 @@ static inline bool compaction_deferred(struct zone *zone, int order) > return true; > } > > +static inline bool driver_page_migratable(struct page *page) > +{ > + return false > +} > #endif /* CONFIG_COMPACTION */ > > #if defined(CONFIG_COMPACTION) && defined(CONFIG_SYSFS) && defined(CONFIG_NUMA) > diff --git a/include/linux/fs.h b/include/linux/fs.h > index a0653e5..2cc4b24 100644 > --- a/include/linux/fs.h > +++ b/include/linux/fs.h > @@ -396,6 +396,8 @@ struct address_space_operations { > */ > int (*migratepage) (struct address_space *, > struct page *, struct page *, enum migrate_mode); > + bool (*isolatepage) (struct page *, isolate_mode_t); > + void (*putbackpage) (struct page *); > int (*launder_page) (struct page *); > int (*is_partially_uptodate) (struct page *, unsigned long, > unsigned long); > diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h > index 91b7f9b..c8a66de 100644 > --- a/include/linux/page-flags.h > +++ b/include/linux/page-flags.h > @@ -649,6 +649,25 @@ static inline void __ClearPageBalloon(struct page *page) > atomic_set(&page->_mapcount, -1); > } > > +#define PAGE_MIGRATABLE_MAPCOUNT_VALUE (-255) > + > +static inline int PageMigratable(struct page *page) > +{ > + return atomic_read(&page->_mapcount) == PAGE_MIGRATABLE_MAPCOUNT_VALUE; > +} I don't like the name. It's boring and overused. Let's call it "mobile" PageMobile() That will be fun. > + > +static inline void __SetPageMigratable(struct page *page) > +{ > + VM_BUG_ON_PAGE(atomic_read(&page->_mapcount) != -1, page); > + atomic_set(&page->_mapcount, PAGE_MIGRATABLE_MAPCOUNT_VALUE); > +} > + > +static inline void __ClearPageMigratable(struct page *page) > +{ > + VM_BUG_ON_PAGE(!PageMigratable(page), page); > + atomic_set(&page->_mapcount, -1); > +} > + > /* > * If network-based swap is enabled, sl*b must keep track of whether pages > * were allocated from pfmemalloc reserves. > diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h > index 3e95fb6..a306798 100644 > --- a/include/linux/pagemap.h > +++ b/include/linux/pagemap.h > @@ -25,8 +25,35 @@ enum mapping_flags { > AS_MM_ALL_LOCKS = __GFP_BITS_SHIFT + 2, /* under mm_take_all_locks() */ > AS_UNEVICTABLE = __GFP_BITS_SHIFT + 3, /* e.g., ramdisk, SHM_LOCK */ > AS_EXITING = __GFP_BITS_SHIFT + 4, /* final truncate in progress */ > + AS_MIGRATABLE = __GFP_BITS_SHIFT + 5, I think this is redudant. Mark at page should be enough. That inode should just provide way for calling migration methods, that's all. > }; > > +static inline void mapping_set_migratable(struct address_space *mapping) > +{ > + set_bit(AS_MIGRATABLE, &mapping->flags); > +} > + > +static inline void mapping_clear_migratable(struct address_space *mapping) > +{ > + clear_bit(AS_MIGRATABLE, &mapping->flags); > +} > + > +static inline int __mapping_ops(struct address_space *mapping) > +{ > + /* migrating page should define all following methods */ > + return mapping->a_ops && > + mapping->a_ops->migratepage && > + mapping->a_ops->isolatepage && > + mapping->a_ops->putbackpage; > +} This is sanity check or debug? You already have mark right at page. You could check them with VM_BUG_ON in some place. > + > +static inline int mapping_migratable(struct address_space *mapping) > +{ > + if (mapping && __mapping_ops(mapping)) > + return test_bit(AS_MIGRATABLE, &mapping->flags); > + return !!mapping; > +} > + > static inline void mapping_set_error(struct address_space *mapping, int error) > { > if (unlikely(error)) { > -- > 1.9.1 > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/